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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright (c) 2008-2009, The KiWi Project (http://www.kiwi-project.eu)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice, 
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright notice, 
 *   this list of conditions and the following disclaimer in the documentation 
 *   and/or other materials provided with the distribution.
 * - Neither the name of the KiWi Project nor the names of its contributors 
 *   may be used to endorse or promote products derived from this software 
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
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 * 
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 */
package kiwi.core.util;

import kiwi.core.model.rdf.KiWiNode;
import kiwi.core.model.rdf.KiWiResource;
import kiwi.core.model.rdf.KiWiTriple;
import kiwi.core.model.rdf.KiWiUriResource;

import java.text.SimpleDateFormat;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

/**
 * @author Sebastian Schaffert
 *
 */
public class KiWiFormatUtils {

	
	public static final SimpleDateFormat ISO8601FORMAT  = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");



    public final static String formatTripleListJSON(Iterable<KiWiTriple> list) {
        HashMap<KiWiResource,Map<KiWiUriResource,List<KiWiNode>>> result = new HashMap<KiWiResource,Map<KiWiUriResource,List<KiWiNode>>>();

        for(KiWiTriple t : list) {
            Map<KiWiUriResource,List<KiWiNode>> propMap = result.get(t.getSubject());

            if(propMap == null) {
                propMap = new HashMap<KiWiUriResource,List<KiWiNode>>();
                result.put(t.getSubject(),propMap);
            }

            List<KiWiNode> nodeSet = propMap.get(t.getProperty());

            if(nodeSet == null) {
                nodeSet = new LinkedList<KiWiNode>();
                propMap.put(t.getProperty(),nodeSet);
            }

            nodeSet.add(t.getObject());
        }

        StringBuilder builder = new StringBuilder();

        builder.append('{');

        for(KiWiResource r : result.keySet()) {
            builder.append(r.toJSON(false));
            builder.append(" : ");
            builder.append("{ ");

            Map<KiWiUriResource,List<KiWiNode>> propMap = result.get(r);
            for(KiWiUriResource p : propMap.keySet()) {
                builder.append(p.toJSON(false));
                builder.append(" : ");
                builder.append("[ ");

                for(KiWiNode o : propMap.get(p)) {
                    builder.append(o.toJSON(true));
                    builder.append(", ");
                }

                builder.append(" ], ");
            }
            builder.append(" }, ");
        }


        builder.append('}');

        return builder.toString();
    }

}
